Horkheimer read Machiavelli as separating man from nature dialectically.

Evidence

The clearest exponent of this view in his eyes was Machiavelli, whose political instrumentalism was used in the service of the rising bourgeois state. Underlying Machiavelli’s politics, Horkheimer maintained, was the undialectical separation of man from nature and the hypostatization of the distinction. In fact, he argued against Machiavelli, “nature” was dependent on man in two ways: civilization changes it and man’s concept of what it is itself changes. Thus history and nature were not irreconcilably opposed. — Martin Jay, The Dialectical Imagination, 775